Just want to add my +1 to the topic.
I'm also a new to hardware but with software development background. I need an input circuit for audio. Then I will do som FFT and beat detection and blink led and lasers until seizure.
Here are link a found so far. You've probably also had.
http://www.instructables.com/id/Arduino-Audio-Input/ - an comprehansive tutorial on how to make a audio input board. It should convert signal to be 5v amplitude with a 2.5V center. But that did not work for me due to probably my curved hands. What I got were only 0 , 1023 and 510-515 values on arduino inputs.
http://macetech.com/store/index.php?main_page=product_info&products_id=11 Arduino input shield. Have not tried yet. Shipment to Germany is more expensive than board itself. But I might buy it in the end.
http://www.andregoncalves.info/ag_blog/?page_id=61 Seems to be the same as previous. I wrote to the man but he just does not reply.
There are few other audio boards out there but they do not provide raw audio data to the board or it is not clear from the description.
Can one suggest a ready to use solution if there is one?